I'd like to propose two advancements for your nice Mod.
Healthstone Module: Let right-click always create the Healthstone while left clicking the icon always consumes the Healthstone. That way, if you received a Healthstone from another warlock that has a different rank of Improved Healthstone and you consumed your own one, you can use the icon the recreate yours instead of consuming the other warlock's Healthstone.
Soul Shard Module: Add an option to always use Drain Soul Rank 1 when clicking the icon. This is especially useful if you're farming (you lose less mana when collecting soul shards) and even more useful if you skilled Improved Drain Soul (you gain mana at the end of a fight, because rank 1 of Drain Soul is much cheaper than the mana you gain from Improved Drain Soul).
I would really love to see these two features in your otherwise perfekt mod.
If you don't have the time (or you just don't want to :)) to implement these features, but still would find them a worthy addition for your mod, let me know so I will try to implement them. I've never done any lua programming before, but maybe it's time to start learning it^^